1. Field of the Invention
The present invention pertains to the art of automatic washing machines and, more particularly, to a washing machine incorporating a control system for counteracting high suds level conditions detected while laundering articles of clothing in the washing machine.
2. Discussion of the Prior Art
The development of suds during operation of an automatic washing machine is a problem that has been recognized in the art. Actually, high levels of suds can form throughout various cycles of a washing operation. In more conventional vertical axis or top-loading washing machines, high levels of suds can be developed during a wash cycle when a water/detergent solution which has a rather high detergent content is placed in turbulence by the operation of an agitator. For front-loading washing machines, the potential of developing high levels of suds can be even greater during wash cycles given the tumbling action of the clothes through the water/detergent solution. In each of these types of known washing machines, high levels of suds can also develop during spin cycles due to the creation of turbulent air when a washing machine basket is rotated at high RPMs. More specifically, during spin cycles the water/detergent solution is directed into a drainage zone by the centrifugal force of the rotating washing machine basket and combines with the turbulent air in the drainage zone to generate suds that can flow back into the basket.
At the end of a wash cycle in either a top or front-loading washing machine, the water/detergent solution is subjected to a drainage operation, followed by a spin period for the washing machine basket. It is desired to remove as much of the water/detergent from the clothes as possible during these steps. Thereafter, the clothes are subjected to various rinse cycles, during which the clothes are agitated or tumbled within fresh water supplied within the basket. Each rinse cycle may also terminate in sequential draining and spinning operations. The development of high levels of suds can be problematic during both the wash and rinse cycles for various reasons. For instance, whenever the washing machine enters a spin mode, the presence of high levels of suds can produce a heavy and possibly excessive load on the motor used to drive the washing machine basket. In addition, the development of high levels of suds may result in a residual water/detergent solution remaining in the laundered clothes, even if several rinse cycles are incorporated in the overall washing operation.
The prior art has addressed this known problem in various fashions. In general, each of the proposed solutions focuses on the reduction of suds during a particular cycle or mode of operation of the washing machine. For example, U.S. Pat. No. 4,410,329 is directed to correcting an over-suds condition that develops during a wash cycle. More specifically, when the over-suds condition is sensed, the wash cycle operation is suspended to enable the clothing and suds in the basket to be sprayed with cold water for a preset period of time and then the clothes are allowed to cool while the bubbles collapse before the washing operation is resumed. Although this arrangement is certainly considered to have some beneficial effects, it suffers from various drawbacks including a prolonged wash cycle. In addition, this patented arrangement only addresses the problem of high levels of suds being developed during a single stage in a wash cycle. Therefore, the possibility exists of high levels of suds carrying forward to subsequent rinse cycles, during which spin modes would be entered with the possible formation of additional suds. Another solution is proposed in U.S. Pat. No. 5,596,889 which is solely directed towards the elimination of high levels of suds produced during spin cycles. In accordance with this patented arrangement, each spinning operation is carried out in multiple stages, with the washing machine basket being rotated at varying speeds during the individual stages. Unfortunately, this patented arrangement also only addresses one potential source of the problem, i.e., the development of suds during spin modes.
Based on the above, there exists a need in the art for a system which will effectively counteract the development of high levels of suds preferably during both wash and rinse cycles of a laundering operation in order to assure the removal of any water/detergent solution from the laundered clothes.